The basic processes for obtaining useful color images from exposed color photographic silver halide materials include several steps of photochemical processing such as color development, desilvering (that usually including silver bleaching and silver halide fixing in separate or a single step), and water washing or dye image stabilizing using appropriate photochemical compositions.
Photographic color developing compositions are used to process color photographic materials such as color photographic films and papers to provide the desired dye images early in the photoprocessing method. Such compositions generally contain color developing agents, for example 4-amino-3-methyl-N-(2-methane sulfonamidoethyl)aniline, as reducing agents to react with suitable color forming couplers to form the desired dyes. U.S. Pat. No. 4,892,804 (Vincent et al.) describes conventional color developing compositions that have found considerable commercial success in the photographic industry. Other known color developing compositions are described in U.S. Pat. No. 4,876,174 (Ishikawa et al.), U.S. Pat. No. 5,354,646 (Kobayashi et al.), and U.S. Pat. No. 5,660,974 (Marrese et al.).
The most common bleaching agents for color photographic processing are complexes of ferric [Fe (III)] ion and various organic chelating ligands (such as aminopolycarboxylic acids), of which there are hundreds of possibilities, all with varying photographic bleaching abilities and biodegradability.
Less common bleaching agents are what are known as peracids including the most common peracid, hydrogen peroxide. These bleaching agents provide some advantages over the more common ferric ion-ligand complexes including reduced environmental concerns. Numerous publications describe peroxide, persulfate, and other peracid bleaching agents and their use in photographic processing. See for example U.S. Pat. No. 5,451,491 (Szajewski et al.), U.S. Pat. No. 5,460,924 (Buchanan et al.), U.S. Pat. No. 5,464,728 (Szajewski et al.), U.S. Pat. No. 5,508,151 (O'Toole et al.), U.S. Pat. No. 5,510,232 (O'Toole), U.S. Pat. No. 5,521,056 (Buchanan et al.), U.S. Pat. No. 5,538,834 (Buchanan et al.), U.S. Pat. No. 5,541,041 (Haye), U.S. Pat. No. 5,547,816 (Fyson et al.), U.S. Pat. No. 5,550,009 (Haye et al.), U.S. Pat. No. 5,554,491 (O'Toole et al.), U.S. Pat. No. 5,578,428 (Fyson), U.S. Pat. No. 5,614,355 (Haye et al.), U.S. Pat. No. 5,641,615 (Haye et al.), U.S. Pat. No. 5,641,616 (Haye et al), U.S. Pat. No. 5,656,416 (O'Toole et al.), U.S. Pat. No. 5,683,858 (Fyson), U.S. Pat. No. 5,691,118 (Haye), U.S. Pat. No. 5,691,112 (O'Toole), U.S. Pat. No. 5,763,147 (Haye et al.), and U.S. Pat. No. 5,773,202 (Haye et al.).
Throughout the photographic industry, there is a desire to provide photographic processing solutions that are safe and easy to use, photographically effective, and environmentally acceptable. One desirable property is that the solutions are not objectionable due to unpleasant odors. In addition, there is a need to stabilize some of the peracid bleaching agents that can decompose upon long-term storage or use and providing rapid bleaching.
Despite the many useful photographic bleaching solutions and processing methods known in the art, there is a continuing need for highly effective photographic bleaching processes that include the use or either peracid bleaching or ferric ion bleaching.
U.S. Pat. No. 5,691,118 (noted above) describes the use of multiple acidic “stop” solutions before and after peroxide bleaching in order to reduce yellow stain in photographic color papers.
More recently, copending and commonly assigned U.S. Ser. No. 10/376,717 (filed Feb. 28, 2003 by Haye and Huston) describes peracid bleaching compositions having increased stability in the presence of a cyclicaminomethanediphosphonic acid or a salt thereof.
While the noted technology provides improvements in the art of photographic processing, there is a continuing need to find ways to stabilize both ferric ion and peracid bleaching compositions without having to incorporate the stabilizing compounds directly within the bleaching compositions.